1. Field of the Invention
The present invention relates in general to the telecommunications field and, in particular, to a wireless communications network, home location register and method for improving a signal strength arbitration scheme to ensure that a mobile terminal is registered at the most appropriate mobile switching center.
2. Background of the Invention
In the telecommunications field, one of the more significant design challenges today involves the development of new signal strength arbitration schemes which can ensure that a mobile terminal is registered to receive and initiate wireless calls with the most appropriate mobile switching center. In the past, a mobile terminal would broadcast a registration access signal that could be received by one or more mobile switching centers (MSCs). These MSCs would forward a registration signal containing information associated with the received registration signal to a home location register (HLR). At this time, the HLRs did not implement a signal strength arbitration scheme for sorting through all the registration signals received from multiple MSCs and, as such, the HLR could register the mobile terminal with a MSC that received a registration access signal having the lowest signal strength of all the received registration access signals. Of course, the MSC that received the registration access signal having the lowest signal strength is not likely to be the most appropriate MSC to support the wireless calls of the mobile terminal. In addition, the HLRs at this time often registered a mobile terminal at multiple MSCs which is not a productive use of valuable resources in a wireless communications network.
Today, most HLRs implement a signal strength arbitration scheme that can collect several registration signals from MSCs and then attempt to select the best MSC on which to register a mobile terminal (see, e.g., TIA/EIA Standard 41.6-D Annex F, dated December 1997). The problem with HLRs that implement the traditional signal strength arbitration schemes, is that the traditional signal strength arbitration scheme requires that the registration signals received by the HLR include an IS41-D parameter known as the ReceivedSignalQuality parameter. If the traditional HLR receives registration signals that contain this ReceivedSignalQuality parameter then the traditional signal strength arbitration schemes would work properly in selecting the best MSC on which to register a mobile terminal. However, traditional HLRs often receive registration signals from MSCs that do not contain the ReceivedSignalQuality parameters and there are no signal strength arbitration schemes currently available that can adequately deal with received registration signals that do not have the ReceivedSignalQuality parameters. In other words, a MSC that transmits a registration signal that fails to contain the ReceivedSignalQuality parameter is not going to be selected by the HLR to service the mobile terminal even though that MSC may be the best MSC on which to register the mobile terminal. In fact, that MSC may be the only MSC that can service the mobile terminal but still it is not registered by the traditional HLR to service the mobile terminal. Accordingly, there is an existing need for a wireless communications network, a home location register and a method that has an improved signal strength arbitration scheme which can ensure that a mobile terminal is registered at the most appropriate mobile switching center. This need and other needs are satisfied by the wireless communications network, home location register and method of the present invention.
The present invention includes a wireless communications network, a home location register and a method having an improved signal strength arbitration scheme which can ensure that a mobile terminal is registered at the most appropriate mobile switching center. In particular, the home location register includes a database coupled to a processor capable of implementing a signal strength arbitration scheme that assigns a provisional quality value to a registration signal that was received from a mobile switching center which failed to include a quality parameter within the registration signal, wherein that mobile switching center may now be considered and possibly registered as the most appropriate mobile switching center to process a wireless call of a mobile terminal that broadcasted a registration access signal to a plurality of mobile switching centers. The most appropriate mobile switching center is often the mobile switching center that has the highest quality value included within or assigned to the registration signal it forwarded to the home location register.